Scientists recently modeled a range of interactions between energy-intensive civilizations and their planets. The results were sobering.

We’re interested in how exo-civilizations develop on their planets. Given that more than 10 billion trillion planets likely exist in the cosmos, unless nature is perversely biased against civilizations like ours, we’re not the first one to appear. That means each exo-civilization that evolved from its planet’s biosphere had a history: a story of emergence, rising capacities, and then maybe a slow fade or rapid collapse. And just as most species that have ever lived on Earth are now extinct, so too most civilizations that emerged (if they emerged) may have long since ended. So we’re exploring what may have happened to others to gain insights into what might happen to us.

We used population biology tools to build a simple model for the evolution of a civilization with its planet. In our approach, the exo-civilization’s population and the planetary environment are braided together by energy use and its consequences. The planet gives the civilization energy resources. The civilization consumes them to do the work of civilization building. As a civilization harvests more power from the planet, its capacities soar. That includes the ability to make and feed more babies. This link between available energy (in the form of food for simple organisms) and rising birth rates is fundamental to population biology.

And for human civilization the steep rise we’ve seen in population is closely tied to fertilizer involving fossil-fuel use. So greater energy will, in the beginning, mean bigger populations. But there’s no free lunch from a planetary perspective. Using all that energy has to result in feedback on the planet. That’s what we earthlings are just starting to see with climate change.

If global warming gets really nasty, everything from energy harvesting to food production is going to get severely stressed and our large human population won’t be sustainable. That’s why our exo-civilization models linked rising planetary impacts with population declines. It was all pretty straightforward, requiring no assumptions about alien economics, sociology, or any other science-fiction ideas.

So, what did the model tell us? We saw three distinct kinds of civilizational histories. The first—and, alarmingly, most common—was what we called “the die-off.” ... In many of the models, we saw as much as 70 percent of the population perish before a steady state was reached. In reality, it’s not clear that a complex technological civilization like ours could survive such a catastrophe....

- Sustainability: For these classes, stable equilibria (n*, e*) exist which can be approached monotonically. The population rises smoothly to a steady-state value. The planetary environment is monotonically perturbed from its initial value e0 and reaches a new steady state that can support a large population.

- Die-off: For these classes, stable equilibria (n*, e*) exist which cannot be approached monotonically. The population overshoots the environment's carrying capacity, reaches a peak, and is forced to decline as the environment reaches its new steady state.

- Collapse: For these classes, stable equilibria with nonzero population do not exist. In these cases the population experiences a rapid decline after reaching its peak value. It is noteworthy that collapse can occur even though the population has begun leveling off due to the civilization's switching from high-impact to low-impact energy modalities.

- Oscillation: In this class, a stable limit cycle exists rather than an equilibrium. The population and the planetary environment cycle between high and low values.

... Claims of impending innovation may be seen (although they are not labeled as such) as being largely aspirational—but the benefits would be great if even just a fraction of their goals were realized during the next generation.

At the same time, these claims should be appraised with unflinching realism.

... Human beings have always sought innovation. The more recent phenomenon is this willingness to suspend disbelief. Credit this change to the effect that the electronics revolution has had on our perceptions of what is possible. Since the 1960s, there has been an extraordinarily rapid growth in the number of electronic components that we can fit onto a microchip. That growth, known as Moore’s Law, has led us to expect exponential improvements in other fields.

However, our civilization continues to depend on activities that require large flows of energy and materials, and alternatives to these requirements can’t be commercialized at rates that double every couple of years. Our modern societies are underpinned by countless industrial processes that have not changed fundamentally in two or even three generations. These include the way we generate most of our electricity, the way we smelt primary iron and aluminum, the way we grow staple foods and feed crops, the way we raise and slaughter animals, the way we excavate sand and make cement, the way we fly, and the way we transport cargo.

Some of these processes may well see some relatively fast changes in decades ahead, but they will not follow microchip-like exponential rates of improvement.

Our world of nearly 8 billion people produces an economic output surpassing US $100 trillion. To keep that mighty engine running takes some 18 terawatts of primary energy and, per year, some 60 billion metric tons of materials, 2.6 billion metric tons of grain, and about 300 million metric tons of meat.

Any alternatives that could be deployed at such scales would require decades to diffuse through the world economy even if they were already perfectly proved, affordable, and ready for mass adoption.

... Vertical farms in cities can produce—profitably—hydroponically grown leafy greens, tomatoes, peppers, cucumbers, and herbs, all with far less water than conventional agriculture requires. But the produce contains merely a trace of carbohydrates and hardly any protein or fat. So they cannot feed cities, especially not megacities of more than 10 million people. For that we need vast areas of cropland planted with grains, legumes, and root, sugar, and oil crops, the produce of which is to be eaten directly or fed to animals that produce meat, milk, and eggs. The world now plants such crops in 16 million square kilometers—nearly the size of South America—and more than half of the human population now lives in cities.

Thanks for posting Vox. Very interesting. Just an observation. I believe at this point the most probable outcome is Dieoff. Because as your posted article stated, we would need decades to fully implement a fully comprehensive substitute for our current FF energy matrix. I think given the state of our planet now, our huge population and our feeble progress to the goal of Alternative/Renewable energy sources, we do NOT have that time anymore. At the same time to not always sound pessimistic, I believe if we can maintain our core technolgical/knowledge base and coherent cohesive societies, we can achieve much to stabilize the situation via restoration and moderation. The wild card is climate change and how much worse will it get.

If every one of us embraces restoration and moderation as the core principles of our human civilisation, then there’s a good chance we’ll be able to pull our planet back from the brink and safeguard the future survival of all life on Earth.

Cog wrote:Life, in all the definitions that define it, are only found on planet earth. Prove me wrong.

So far. But of course, we don't know how to look closely yet outside our solar system. Until recently we didn't even know for sure that any planets existed outside our solar system. Or going back a little further, that there were even galaxies outside our own.

Given that the entire history of science vs. religion has basically been realizing planet earth is less and less unique and special than religious beliefs have assumed, why should life be any different.

In a known universe with on the order of a trillion galaxies and roughly a quarter of a trillion stars per galaxy on average, what are the odds our earth is the only planet unique enough to have life? That's roughly 250 billion trillion stars, which given the known exoplanets imply one HELL Of a lot of planets.

Probability says science will very likely prove you wrong, if humans can manage not to destroy themselves in short order (i.e. a handful of centuries or so).

Given the track record of the perma-doomer blogs, I wouldn't bet a fast crash doomer's money on their predictions.

Cog wrote:Life, in all the definitions that define it, are only found on planet earth. Prove me wrong.

God can do anything He chooses so we can not 'prove' He has not scattered life all through the galaxy and/or universe. Much like faith in God for those who choose not to believe you must always consider that 'Absence of evidence is not evidence of absence!'

I should be able to change a diaper, plan an invasion, butcher a hog, design a building, write, balance accounts, build a wall, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, pitch manure, program a computer, cook, fight efficiently, die gallantly. Specialization is for insects.

I think life on Earth came from the Universe. It is very likely that viruses rain down from space. So rather than DNA occurring spontaneously in a swamp, life just built on the existing stock.

If that's true, not only is life all over the universe, we are related to it Tanada - Who's to say whose grand design that was?

It's all about connections...We are the aliens

A Solar fuel spill is otherwise known as a sunny day!The energy density of a tank of FF's doesn't matter if it's empty.I will see your google and raise you an infinity!https://monitoringpublic.solaredge.com/solaredge-web/p/kiosk?guid=19844186-d749-40d6-b848-191e899b37db

Cog wrote:Life, in all the definitions that define it, are only found on planet earth. Prove me wrong.

That is a rather narrow view

It is a view that is supported by the available evidence at this point in time. No where have we found evidence of life outside of the planet we live on. No radio communication, no space-craft, No light beam signaling, nothing so far. Even on Mars, which we know had water and conditions suitable for life, have we found so much as a single rock containing fossils of algae.

Cog wrote:Life, in all the definitions that define it, are only found on planet earth. Prove me wrong.

God can do anything He chooses so we can not 'prove' He has not scattered life all through the galaxy and/or universe. Much like faith in God for those who choose not to believe you must always consider that 'Absence of evidence is not evidence of absence!'

Or God could have said, in only this place only(earth) will I form life. Everywhere else, all the billions of galaxies and trillions of stars, quadrillions of planets, are simply created for mankind to look at in the night sky.

Why is it so scary that we could not only be the only intelligent life-form in the universe but the only life-form in the universe? Doesn't scare me.

Cog wrote:Life, in all the definitions that define it, are only found on planet earth. Prove me wrong.

God can do anything He chooses so we can not 'prove' He has not scattered life all through the galaxy and/or universe. Much like faith in God for those who choose not to believe you must always consider that 'Absence of evidence is not evidence of absence!'

Or God could have said, in only this place only(earth) will I form life. Everywhere else, all the billions of galaxies and trillions of stars, quadrillions of planets, are simply created for mankind to look at in the night sky.

Why is it so scary that we could not only be the only intelligent life-form in the universe but the only life-form in the universe? Doesn't scare me.

Why is it so scary that "God" might be a figment of man's imagination?

Given the track record of the perma-doomer blogs, I wouldn't bet a fast crash doomer's money on their predictions.

Being alone as the only living planet in the universe or being one of billions of living planets, either way the immensity of empty space between these isolated balls of life only reinforces how unimportant each of us are with our lofty opinions of a god filled or godless universe.

Our resiliency resembles an invasive weed. We are the Kudzu Apeblog: http://blog.mounttotumas.com/website: http://www.mounttotumas.com

I think it makes a big difference what kind of continental pattern other worlds have. If a world has life, and that world has one supercontinent, then refugee populations essentially have few barriers. If there are many separate continents, then that would be harder. Take our world, it has a too close Africa and Europe problem right now. They are connected both by land, through Asia, and the fact that the Mediterranean Sea can be pretty easily crossed. Fewer would try the entire Atlantic in order to reach the Americas, especially in some rickety boat. The US may have had a problem with Haitians at one point, and Cubans (though they got asylum just by touching the beach), but it hasn't had to deal with the kind of crisis Europe is facing. You can compare that to the land border, where Trump wants to build a wall!

Land formation has also had a huge impact upon political dominance locally and to what extent local power can be projected globally. It's harder to rule, let alone make an empire, of an entirely land bordered domain. It could be that, however, when such powers get going they tend to operate a certain way. They may, at some remove and after some luck, embrace diversity. That could be important in the development of ideas.

Cog wrote:Life, in all the definitions that define it, are only found on planet earth. Prove me wrong.

That is a rather narrow view

It is a view that is supported by the available evidence at this point in time. No where have we found evidence of life outside of the planet we live on. No radio communication, no space-craft, No light beam signaling, nothing so far. Even on Mars, which we know had water and conditions suitable for life, have we found so much as a single rock containing fossils of algae.

I think this is more analogous to when we believed the Earth was flat from lack of any contradictory info and because the Church said so. We are far too novice and ignorant of what may or may not be out there, in the vastness of the Cosmos. We should have the humility to accept an agnostic position

The materials or stardust that make up this planet aren't unique. If the conditions are right for an earth like planet in say 1 out of 1000 stars. Then that makes about 1 with 20 zeros after it of planets that are habitable for life in the Universe.

As far as aliens, I don't believe life evolves significantly much further in physical reality from where we are at.

Climate change is far too complex for any physical being to completely understand.

OK, this is a deep discussion in very few words. My opinion is 'out there' as usual. But you ain't seen nothin' yet...

My instincts say whenever we meet aliens they will have DNA. Evolution will proceed in a similar fashion everywhere. All tool users need at least two hands to tighten a bolt. MM is right. We are a well designed species that evolved under the same constraints as every other species. We are not special...but we're not done yet.

Ibon wrote:the immensity of empty space between these isolated balls of life

Space really isn't empty. It's teaming with photons and EM fields, gravitons and gravitational fields, Quarks, Leptons, Neutrinos, and this cool stuff called Dark-Matter. Some of that dark matter is viruses

One day we may hitch a ride on a gravitational field and hop over to the next planet.

Cog wrote:Or you could make the counter-argument that God loved mankind so much, he created the entire universe just for us. Thus, us humans are the most important thing around. At least from his perspective.

I don't like this concept. It leads to elitism. Next step is 'God loves me more than you, so why should I care about you?' I'm not convinced God exists, but if he does he loves me just a much as you and that goes for all the aliens around here.

You don't think Mother Nature exists...but she is still as indifferent to you as she is to me We are in this together.

mmasters wrote:Then that makes about 1 with 20 zeros after it of planets that are habitable for life in the Universe.

I will see your google and raise you an infinity.

I think the Big Bang was a local phenomena in an infinite universe. I like the Steady State theory better. The speed of light prevents us from looking outside our local area. Is there a speed of gravity? This would explain why the expansion of the known universe is accelerating. The gravity of the infinite universe is tearing our little bubble apart...

There are an infinite number of earth like worlds. There are an infinite number of advanced species. And there are an infinite number of ways for them to kill themselves off. I don't think God or Mother Nature would put all his/her eggs in one basket.

Ain't life grand?

A Solar fuel spill is otherwise known as a sunny day!The energy density of a tank of FF's doesn't matter if it's empty.I will see your google and raise you an infinity!https://monitoringpublic.solaredge.com/solaredge-web/p/kiosk?guid=19844186-d749-40d6-b848-191e899b37db